Platen printing machine



L. GERARD PLATEN PRINTING MACHINE Filed March 21, 1939 4 Sheets-Sheet 1 Aflorney,

y 1940- L.- GERARD 2,200,920

I PLATEN Immune MACHINE Filed March 21, 1939 4 Sheets- Sheet 2 May 14, 1940. L. GERARD 2,200,920

PLATEN PRINTING MACHINE Filed March 21, 1939 4 Sheets-Sheet 3 A; zlofneysy 4, L. GERARD 2;2o0;920

PLATEN PRINTING MACHINE Filed March 21, 1939 4 Sheets-Sheet 4 /n ven (or Wmvfij A Alfornevs. I

Patented May 14, 1940 PATENT OFFICE PLATEN PRINTING MACHINE Ludwig Gerard, Mannheim-Feudenlieim, Germany Application March 21, 1939, Serial No. 263,244 In Germany April 19, 1938 4 Claims.

This invention relates to a platen printing machine for the production of all kinds of ink cloth printing. It is particularly suitable for the printing of forms which are required for informing the workers for carrying out work. Hitherto such forms Were first typed in original on a type writer and then duplicated by means of duplicating and transfer process.

A method is known for preparing data for carrying out work and similar papers bearing approximately the same text. According to this method the text is embossed in strips of metal or other suitable material of a width and length corresponding to the text arrangement, and these strips are then assembled in a text frame to the desired text composition. The apparatus used for carrying out this method is a platen printing machine with an eccentrically mounted cylinder, shiftable on rails in combination with a paper magazine and casing and with an automatically winding and unwinding ink cloth stretched over the printing bed. On one longitudinal side of the bed a fiat bar, and on the opposite longitudinal side an abutment bar of angular vertical section are arranged under which bars the text frame is to be slipped so that it rests on the printing bed under the ink cloth and covers practically the whole printing bed. This text frame serves as carrier for the text strips in which the text is embossed. In this machine the sliding device (carriage) is pulled forward with the rubber pressure cylinder and with the paper magazine on the horizontal rails by means of a handle, the next paper form to be printed being at the same time taken from the magazine, placed on the printing bed and during the return movement of the carriage pressed by means of the pressure cylinder on to the ink cloth and therefore indirectly on to the text and printing bed.

This manner of moving the carriage with the cylinder and paper magazine and of the printing is open to many objections. Firstly it is only possible to work relatively slowly with such pulling and pressing movements. This manner of moving requires relatively great physical strength and continuous service results in the strength of the person operating the machine being taxed very considerably. Consequently the number of forms which can be printed in a given unit of time is very restricted. Such machines are therefore only suitable for the printing of a relatively small number of forms in a short period of time.

The construction of the ink cloth feeding de- (Cl. 101--273) .L:

vice depends on the manner and means of moving the carriage. Hitherto, the ink'cloth was only fed by means of a relatively complicated frame. Consequently, the unwinding from a roller only takes place slowly and is very often irregular in the case of quick work.

These objections in platen printing machines, especially those which are intended for printing instruction for carrying out work, are overcome by the machine according to the invention which 10 has a novel feed for the carriage carrying the rubber cylinder and the paper magazine.

The invention consists in that this movement of the carriage is no longer eifected on horizontal rails arranged above the printing bed, but the 15 carriage during its forward movement runs on an ascending, rocking track located below the printing bed and during its return movement on a horizontal track under the ascending track. The rocking track is preferably constructed as a steel 29 rib. It is in the form of a two-armed lever with arms of unequal lengths and whose upper surface forming the track has a long, gradually ascending curve and a short, suddenly descending curve. ihe point of support of the lever is preferably 25 just below the commencement of the descent of the track. The moment the carriage moving on rollers or the like has passed the highest point and the point of the track which is above the supporting point of the lever, the shorter lighter arm 30 of the lever descends, preferably in tensioning a spring which connects it to the under side of the printing bed, so that the rollers carrying the carriage run into a catching device and thus come under the former path steel rib. During the 35 return movement the rollers thereof run under the steel rib on a second rail located thereunder, until the carriage reaches its initial position.

Novel feeding device for the ink cloth is combined with this movement of the carriage. The 4 moment the roller of the carriage returns into its initial position, the higher, preferably longer arm of the lever which serves for actuating an ink cloth feed wheel is depressed, so that the shorter arm is brought into engagement with the wheel 45 was hitherto effected by' a somewhat complicated lever mechanism which had to be set in operation by the carriage striking the front 'or rear abutment bar. In the present instance only a single lever and a single wheel are required for driving the ink cloth rollers. The ink band feeding mechanism is therefore of much simpler construction.

The novel mode of moving the carriage on a track mounted like a lever enables the mechanism to be constructed by a simple feed motion which is effected by means of a feed lever mounted on the front of the machine. This lever drives a tooth gear which sets in motion a worm gear spindle with worm thread by which a preferably slightly tapered roller is moved on which the carriage with the rubber cylinder and paper magazine is mounted. When the lever is in the vertical position the carriage is for example over the rear wide side. If the lever is swung down, out of its vertical position into horizontal position for example in clockwise direction, the carriage rolls forward on the ascending track until it reaches the highest point and in running down from this point it is caught by the catching device. During this operation a sheet of paper is pulled out of the paper magazine and deposited on the ink band and consequently indirectly on the text frame and on the printing bed. If the feed lever is swung back into its initial vertical position, the carriage rolls forward on the horizontal rail below the rocking track and causes the cylinder to press against the paper and to effect the actual printing thereof.

When the carriage is moved in this manner by means of the lever at the front of the machine, large numbers of sheets can be printed without tiring the operator because the lever, being arranged on the front of the machine, can be operated with both hands. A lever is also relatively easy to operate. By the arrangement of the lever and of the rails below the printing bed, the printing bed is free on three sides so that a text frame can be fixed on the printing bed by slipping from the side.

An objection to the known machine is that when it is .desired to prevent certain portions from being printed it is necessary to remove the corresponding strips of text separately or in the case of platen presses'operating with pressure pads the portion of the rubber pad opposite the portion to be left blank must be removed to prevent this portion from. being printed. It is evident that this measure takes a considerable time because the whole carriage and paper magazine must be first swung up to expose the ink cloth.

To overcome this objection it is proposed according to the invention to cover the portions which are not to be printed by placing covering slips over the text strips in the interval between the printing of two sheets, without removing the text frame.

' An embodiment of the invention is illustrated by way of example in the accompanying drawings in which:

Fig. 1 shows the machine in front elevation with raised ink cloth protecting cover,

Fig. 2 is a side elevation of the machine with lowered ink cloth protecting cover, j

Fig. 3 is a section on line III-III of Fig. 1, but without paper magazine,

Fig. 4 is a section on line IV-IV of Fig. 2,

Fig. 5 shows a printing bed in top plan view,

Fig. 6 is a section on line V IV'I of Fig. 5, l e ,.,Fig..7. is a sect n on e VII-.VHof ie.

A steel plate 15 forming the printing support proper, rests on a base a. The texts embossedonthin metal plates in the form of sheets are pref erably fitted together beforehand in the text frame and this frame is slipped on to the printing plate b under a steel bar 12 on one of the longitudinal sides of the printing plate h, under an inking cloth 0, until it comes into contact with an abutment bar I) on the other longitudinal side of the printing plate I) and which arrests the movement of the text frame or text strips.- On the front side of the machine there isa lever d which, on being turned through a quarter of a revolution, imparts rotation to the spur wheel e fixed thereon and to another spur wheel ,1 meshing therewith. Owing to the ratio of transmission the small wheel f performs a complete revolution while the lever is moving through a quarter revolution and compels the spindle worm g fitted thereon to carry out a complete revolution during this time. A tapered roller h which is fixed on the carriage i by means of a bolt runs in the tapered worm gear 9. The bore 2' in the carriage serves to accommodate the roller 71. on its entire length. The spindle g rests on ball bearings 7' whosebearing space is closed by a removable cap to enable the removal of the spindle. A weak spring is, which is loosely mounted in the bore 1' in the carriage and surrounds the bolt h carrying the roller h, is intended to accelerate the dropping of the roller h. 1

Simple cylindrical supporting rollers 1 are fixed on the inner side of the carrier 2' by means of bolts.

The paper magazine is fixed on the carriage 2' by means of screws. The paper can be introduced either vertically or horizontally to suit requirements.

If the lever is swung through a quarter revolution in clockwise direction, the roller I, which carries the carriage z with the rubber cylinder 'm and paper magazine n, runs forward on the steel rib 0 having a curved upper surface, and mounted like a lever with its supporting point go below in which position it is indicated by dash lines in Fig, 3 of the drawing.

A horizontal rail track 1" extends from this catching device 1' under the curved rib 0.. The moment the roller Z runs into the catching device 1 the steel rib o is freed from its load and springs up under the action of the spring q, that is returns into its initial position at the same time freeing the path for the movement of the roller 1 along the rail 1' under the steelrib 0.

If the lever d is now returned into its vertical initial position, the roller Z'runs under the steel,

rib 0 on the horizontal bar r until it comes into contact with the longer armsl of a lever whose end is so shaped that it conforms to the curvature of the roller Z. The lever s is somounted that the upwardly directed point s of its-shorter arm engages the teeth of a ratchet wheel t, when the point of the longer arm 8 of the lever is depressed by the load of the roller Z This ratchet wheel t is fixed on a roller u by which the-ink cloth, is wound, w ereas. a se ond ro lsw? 91 1 t opposite side of the machine serves for unwinding the ink cloth. Underneath the lever s there is preferably a spring which causes the longer arm .9 of the lever to swing up again at the next feed motion. The moment the roller 1 is forced through the space between the rib and the longer arm s of the lever s, the lever arm s descends under the pressure exerted by the roller Z. At the same time the lever arm :3 is swung upwards and its point engages the ratchet wheel t, feeding it through a part revolution. By this movement the ink cloth 0 unwinds from the roller u and winds on the roller u a length equal to about the space between two lines. In the meantime the roller I has reached its initial position and the sequence of operations can be repeated by again actuating the lever (Z.

By the movement of the lever the carriage mounted on the roller Z with the pressure cylinder m and the paper magazine n can be advanced without touching the ink cloth, taking the next paper form to be printed from the paper magazine n in known manner and placing it on the printing bed 11, whereupon during the return movement of the lever the paper sheet is pressed by the cylinder m on to the ink cloth and the printing plate and is thereby printed.

When it is desired to print only a portion of the text in the frame, the text which is not to be printed is covered over. An advantageous manner of effecting-this is illustrated in Figs. 5 to 7 in which a row of uniformly spaced pins 0 is arranged along the upper side of the bar b and cover strips w having a hole near one end are slipped on to the pins adjacent the line or lines of text which are not to be printed. The upper side of the abutmentbar b is preferably constructed so that the other end of these cover strips w can be fitted into a slot b extending the whole length of the bar 22 Thus when the paper to be printed is pressed against the ink cloth by the pressure cylinder m, only those portions of the frame which are not covered by strips 20 will be printed on the paper by the ink cloth 0.

It is evident that by suitable arrangement of pins '0 along one end of the bed and of an additional abutment bar at the other end of the bed the cover strips can be secured in the longitudinal direction of the bed. The steel bed also has along its longitudinal and transverse edges a scale to enable the lines which it is desired to cover to be quickly located.

I claim:

1. A platen printing machine comprising in combination a printing bed, printing forms with raised embossed text removably insertable in said bed, an ink cloth stretched on said bed over said forms, a carriage reciprocable in the longitudinal direction of said bed, a paper magazine mounted on said carriage and adapted to feed a sheet of paper on to said ink cloth at each reciprocation of said carriage, a pressure roller journalled on said carriage and adapted to press the fed sheet of paper against said ink cloth and consequently against said forms to print the text on the sheet of paper, a double track formed under said printing bed and comprising a rocker track in the form of a lever with two unequal arms and having a gradually ascending curve merging into a suddenly descending curve, a pivot pin supporting said lever just after the beginning of said descending curve, and a horizontal track extending under said rocker track, rollers supporting said carriage on said rocker track during the out- Ward movement of said carriage and on said horizontal track during the return movement of the carriage.

2. In a platen printing machine as specified in claim 1, a catching device formed at the end of the horizontal track below the steeply descending curved end of said rocker track, said catching device adapted to catch the rollers running off the end, of said rocker track and to guide them on to said horizontal track.

3. In a platen printing machine as specified in claim 1, an ink cloth feeding device, comprising a bell-crank lever oscillatably mounted at the front end of the horizontal track and having a long horizontal arm whose end is shaped to conform to the periphery of the roller and in alignment with the front end of the gradually ascending curved end of the rocker track, and a short vertical arm with upwardly directed point, said lever adapted to be rocked under the load of said roller carrying the carriage, a spring acting on said lever to return it into its initial position, a ratchet wheel in the range of movement of the pointed end of the short arm of said lever and adapted to be rotated by the oscillation of said lever under the weight of said roller, a winding roller rigidly connected to said ratchet wheel, an unwinding roller at the other end of the machine, and an ink cloth extending from said unwinding roller over the printing bed and on to said winding roller and adapted to unwind from said unwinding roller and wind on said winding roller according to the rotation of said ratchet wheel by said lever.

4. In a machine as specified in claim 1, the carriage having a bore in its under side, a bolt screwed into said carriage and extending through said bore, a roller on said bolt, a spring in said bore loosely surrounding said bolt and pressing said roller in outward direction on said bolt, a spindle journalled in ball bearings below the horizontal track and having a helical groove in which said roller engages, a lever oseillatable on the front end of the machine, and a transmission gear between said spindle and lever adapted to rotate said spindle at the oscillation of said lever to shift said carriage through the intermediary of said roller engaging in said helical groove.

LUDWIG GERARD. 

